I wouldn’t get too hung up on the cult comparison. It’s not an exact one-to-one. QAnon is a new phenomenon and there’s no perfect facsimile of it anywhere in the academic literature.
I’m not predicting that they will go Heaven’s Gate en masse, but at least one of these wingnuts will murder someone after the election and probably some time before it. Unlike other cults, they’re atomized and decentralized.
The leader doesn’t exert the same direct control that could lead to a Jonestown or something like the Tokyo Sarin Gas Attacks but at the same time, there’s no organized group to inhibit individuals from going out on their own or from misinterpreting some cryptic message from Q as a call to violence.
As I pointed out in another reply, someone was arrested for making thousands of death threats against Democrats literally the next week. While QAnon is a fringe of a fringe, a lot of the same basic elements, like belief in a “Deep State” conspiracy, throughout the bulk of Trump’s primary base. Any one of them could go down a path of radicalization at any time.